Loading...
| Friend's email | |
| Your name | |
| Your email | |
| enter code | |
This page was sent successfuly
- Type of Document: M.Sc. Thesis
- Language: Farsi
- Document No: 39175 (08)
- University: Sharif University of Technology
- Department: Mechanical Engineering
- Advisor(s): Durali, Mohammad
- Abstract:
- In this research, acoustic field around an underwater vessel generated by different sources is studied. Hull vibration due to harmonic forces from rotating machinery inside the vessel, flow induced noise due to flow around the hull, and propeller generated noise were considered. Finite Element Method (FEM) was used to determine hull vibration due to mechanical excitations by internal machinery. A 3-D boundary element computer code was then developed to solve Helmholtz equation in the surrounding water by which Acoustic field around the vessel was then obtained. To calculate flow induced noise and propeller noise, Navier-Stocks equations with LES turbulent model was solved around the vessel body using a commercially available CFD code. The resulting pressure fluctuations in the flow field around the vessel was used to in solving Lighthill equation by a developed FEM Code that yield flow induced acoustic field. It was found that the noise generated by the propeller has the highest level in the filed. Moreover the noise generated by the machinery, containing signified frequencies, can be considered as the most important source in the detection of underwater vessel
- Keywords:
- Finite Element Method ; Computational Fluid Dynamics (CFD) ; Boundary Element Method ; Mechanical Noise ; Hydrodynamic Noise ; Acoustic Field ; Lighthill Equation
Digital Object List
-
محتواي پايان نامه
- view
Bookmark